I have both a Roku 3 and an older Roku HD. Everything has been working great and then I moved recently. My older Roku HD was unplugged for about a month and I tried to set it up today and something is wrong. I only get a flashing white light on the front of the device and on the tv there is No Signal. Nothing has changed with my wireless network. Same network name and password. I have tried unplugging the power cord and letting it sit for 30 seconds and plugging it back in. I have tried a soft reset using a paper clip in the reset hole on the bottom and that hasn't helped. I have changed the batteries in the IR remote... nothing. I had the same issue when I first connected the Roku 3, but it sorted itself out fairly quickly once I was able to sync up my remote.
Any advice is welcome. Just remember that I can't get anything on the screen so futzing with the menu isn't possible. I have nothing on the tv screen.